Composition Containing a Block Copolymer and a Method of Lubricating an Internal Combustion Engine

ABSTRACT

The invention provides a lubricating composition containing an oil of lubricating viscosity and a block copolymer. The block copolymer may contain (a) a hydrophobic first block having C 1-30  alkyl (meth)acrylic units, wherein at least 50 wt % of the C 1-30  alkyl (meth)acrylic units are C 12-15  alkyl (meth)acrylic units, and up to 50 wt % of the C 1-30  alkyl (meth)acrylic units are C 16-20  alkyl (meth)acrylic units, with the proviso that alkyl groups of the C 1-30  alkyl (meth)acrylic units have an average total number of carbon atoms of at least 8; and (b) a second block having (meth)acrylic units further having a heteroatom-containing group providing a polar group. The invention further relates to a method of lubricating an internal combustion engine by lubricating the engine with the lubricating composition. The invention further relates to the use of the block copolymer as an emulsifier and/or pour point depressant.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of application Ser. No. 15/249,873filed on Aug. 29, 2016, which is a continuation of application Ser. No.13/127,114 filed on Jul. 11, 2011 which claims priority to PCTApplication Serial No. PCT/US2009/063046 filed on Nov. 3, 2009 whichclaims benefit to Provisional Application Ser. No. 61/111,408 filed onNov. 5, 2008, the entirety of all of which is hereby incorporated byreference.

FIELD OF INVENTION

The invention provides a lubricating composition containing an oil oflubricating viscosity and a block copolymer. The invention furtherrelates to a method of lubricating an internal combustion engine bylubricating the engine with the lubricating composition. The inventionfurther relates to the use of the block copolymer as an emulsifierand/or pour point depressant.

BACKGROUND OF THE INVENTION

Lubricants are often exposed to contaminant amounts of water. Thecontaminant amounts of water are believed to be caused by ingress ofwater through equipment seals during operation, or from combustionby-products that pass into the crankcase via blow-by. The water may forma second layer in the lubricant. Typically to reduce the formation ofthe second layer emulsifiers and/or dispersants are employed. If thewater concentration becomes high enough, an emulsion results. If theemulsion is unstable, the contaminant water may then cause additionaldifficulties such as corrosion. The corrosion may be from copper or leadbearings, or iron.

In addition to the need for an emulsifier, lubricant base oils may alsocontain waxy components. Waxes may agglomerate and cause accumulation ofcrystals in a lubricant. When this occurs, problems arising includereduced low temperature oil pumpability, poorer cold temperatureproperties or reduced fuel economy. Accordingly, in one embodiment itmay also be desirable to employ a pour point depressant that reduces waxagglomeration.

In flexible fuel vehicles (FFVs) the internal combustion engine isdesigned to run on gasoline or a blend of up to 85% ethanol (E85).Except for a few engine and fuel system modifications, they areidentical to gasoline-only models. Traditionally, dispersants aredesigned to stabilise contaminants in the engine oil of gasoline-fuelledcars. Fuelling with E85 introduces the potential to transform the engineoil into a milky emulsion. In order to overcome the formation of anunstable milky emulsion, it would be desirable to employ an emulsifier.

International publication WO2006/047393 discloses linear and star RAFTpolymers as viscosity index improvers in a variety of lubricants. TheRAFT polymers may have a variety of architectures including diblockcopolymers. All of polymers are derived from C₁₂₋₁₅ alkyl(meth)acrylates. There is no disclosure or teaching of linear or starpolymers having emulsifier and/or pour point depressant properties.

US Patent Application 2006/0189490 discloses a lubricating compositioncontaining base oil and at least one additive having friction-modifyingproperties. The additive is a linear diblock copolymer which includeshydrophobic segments P and polar segments D, said hydrophobic segmentsbeing obtained by polymerisation of monomer compositions which comprises0 to 40% of C₁₋₅ alkyl (meth)acrylates, 50 to 100% of C₆₋₃₀ alkyl(meth)acrylates, and 0 to 50% of a polar group containing ester,thioester or amide functionality. All of the examples disclose C₁₂₋₁₅alkyl (meth)acrylates. There is no disclosure or teaching of linear orstar polymers having emulsifier and/or pour point depressant properties.

SUMMARY OF THE INVENTION

The inventors of this invention have discovered that a lubricatingcomposition containing a block copolymer and method as disclosed hereinis capable of providing acceptable levels of at least one of (i)emulsifying properties, and (ii) pour point depressant properties. Inone embodiment the lubricating composition containing the blockcopolymer provides both emulsifying properties and pour point depressantproperties.

As used herein, the term “polar” in the state of the art is used in theordinary sense of the word and is also known to mean hydrophilic.

In one embodiment the invention provides a lubricating compositioncomprising an oil of lubricating viscosity and a diblock copolymer,wherein the diblock copolymer comprises:

-   -   (a) a hydrophobic first block having C₁₋₃₀ alkyl (meth)acrylic        units, wherein at least 50 wt % of the C₁₋₃₀ alkyl (meth)acrylic        units are C₁₂₋₁₅ alkyl (meth)acrylic units, and up to 50 wt % of        the C₁₋₃₀ alkyl (meth)acrylic units are C₁₆₋₂₀ alkyl        (meth)acrylic units, with the proviso that alkyl groups of the        C₁₋₃₀ alkyl (meth)acrylic units have an average total number of        carbon atoms of at least 8; and    -   (b) a second block having (meth)acrylic units which further have        a non-carbonyl heteroatom-containing group providing a polar        group to such units, whereby said second block exhibits greater        hydrophilicity than does the hydrophobic first block.

The second block having (meth)acrylic units which further have anon-carbonyl heteroatom-containing group providing a polar group to suchunits, whereby said second block exhibits greater hydrophilicity thandoes the hydrophobic first block, may also be described as a secondblock having (meth)acrylic units further having a heteroatom groupproviding a polar group.

In one embodiment the invention provides a lubricating compositioncomprising an oil of lubricating viscosity and a diblock copolymer,wherein the diblock copolymer comprises:

-   -   (a) a hydrophobic first block having C₁₋₃₀ alkyl (meth)acrylic        units, wherein at least 50 wt % of the C₁₋₃₀ alkyl (meth)acrylic        units are C₁₂₋₁₅ alkyl (meth)acrylic units, and up to 50 wt % of        the C₁₋₃₀ alkyl (meth)acrylic units are C₁₆₋₂₀ alkyl        (meth)acrylic units, with the proviso that alkyl groups of the        C₁₋₃₀ alkyl (meth)acrylic units have an average total number of        carbon atoms of at least 8; and    -   (b) a second block having (meth)acrylic units which further have        a non-carbonyl heteroatom-containing group providing a polar        group to such units, whereby said second block exhibits greater        hydrophilicity than does the hydrophobic first block.

In one embodiment the invention provides a diblock copolymer product(and optionally a lubricating composition) obtained/obtainable by aprocess comprising:

-   -   (1) contacting:        -   (i) a free radical initiator;        -   (ii) a chain transfer agent (typically containing a            thiocarbonyl thio group useful in RAFT polymerisation            processes); and        -   (iii) one or more C₁₋₃₀ alkyl (meth)acrylic monomer units,            wherein at least 50 wt % of the C₁₋₃₀ alkyl (meth)acrylic            monomer units contain C₁₂₋₁₅ alkyl (meth)acrylic units, and            up to 50 wt % of the C₁₋₃₀ alkyl (meth)acrylic units are            C₁₆₋₂₀ alkyl (meth)acrylic units, with the proviso that            alkyl groups of the C₁₋₃₀ alkyl (meth)acrylic units have an            average total number of carbon atoms of at least 8, to form            a polymer; wherein the process of step (1) is typically a            controlled radical or other living polymerisation process            with living characteristics (for instance a controlled            radical polymerisation process); and at least about 50 wt %            of the polymer chains from step (1) contain a reactive end            group capable of reacting with a polyvalent coupling agent;    -   (2) optionally contacting the polymer of step (1) with a        polymerisation inhibitor;    -   (3) contacting the polymer of step (1) or step (2) with one or        more (meth)acrylic units typically at least 50 wt % or at least        75 wt % of the said units further containing a        heteroatom-containing group; and    -   (4) optionally mixing the polymer of step (3) with an oil of        lubricating viscosity to form a lubricating composition.

In different embodiments the C₁₆₋₂₀ alkyl (meth)acrylic units may beC₁₆₋₁₈ alkyl (meth)acrylic units, or C₁₈₋₂₀ alkyl (meth)acrylic units.The C₁₆₋₂₀ alkyl (meth)acrylic units may also contain up to 10 wt % (ortypically up to 5 wt %) of C₁₄ alkyl (meth)acrylic units. In oneembodiment the C₁₆₋₂₀ alkyl (meth)acrylic units may be in the form of amixture of (meth)acrylic compounds having alkyl groups containing 16 to20, or 16 to 18 carbon atoms.

In the process described above, the first step of the process may beperformed in the presence of a mineral oil, synthetic oil, hexane,toluene, tetrahydrofuran, or other known polymerisation solvents.

In one embodiment the invention provides a diblock copolymer product(and optionally a lubricating composition) obtained/obtainable by aprocess comprising:

-   -   (1) contacting:        -   (i) a free radical initiator;        -   (ii) a chain transfer agent (typically containing a            thiocarbonyl thio group useful in RAFT polymerisation            processes); and        -   (iii) with one or more (meth)acrylic units typically at            least 50 wt % or at least 75 wt % of the said units further            having a heteroatom-containing group,            wherein the process of step (1) is typically a controlled            radical or other living polymerisation process with living            characteristics; and at least about 50 wt % of the polymer            chains from step (1) contain a reactive end group capable of            reacting with a polyvalent coupling agent;    -   (2) optionally contacting the polymer of step (1) with a        polymerisation inhibitor;    -   (3) contacting the polymer of step (1) or step (2) with one or        more C₁₋₃₀ alkyl (meth)acrylic monomer units, wherein at least        50 wt % of the C₁₋₃₀ alkyl (meth)acrylic monomer units contain        C₁₂₋₁₅ alkyl (meth)acrylic units, and up to 50 wt % of the C₁₋₃₀        alkyl (meth)acrylic units are C₁₆₋₂₀ alkyl (meth)acrylic units,        with the proviso that alkyl groups of the C₁₋₃₀ alkyl        (meth)acrylic units have an average total number of carbon atoms        of at least 8, to form a polymer; and    -   (4) optionally mixing the polymer of step (3) with an oil of        lubricating viscosity to form a lubricating composition.

In the process described above, the first step of the process may beperformed in the presence of a solvent such as toluene ortetrahydrofuran.

The processing temperatures, pressures and reagents are known to aperson skilled in the art of controlled radical polymerisationtechniques. References describing such materials include WO2006/047393and the various references disclosed herein below in the description ofthe diblock copolymer.

In one embodiment the invention provides block copolymer obtained (orobtainable) by the process described above.

In one embodiment the invention provides a method of lubricating aflexible fuel vehicle (flex fuel vehicle or FFV) internal combustionengine comprising supplying to the engine a lubricating compositioncomprising an oil of lubricating viscosity and a block copolymer,wherein the block copolymer comprises:

-   -   (a) a hydrophobic first block having C₁₋₃₀ alkyl (meth)acrylic        units, with the proviso that alkyl groups of the C₁₋₃₀ alkyl        (meth)acrylic units have an average total number of carbon atoms        of at least 8; and    -   (b) a second block having (meth)acrylic units which further have        a non-carbonyl heteroatom-containing group providing a polar        group to such units, whereby said second block exhibits greater        hydrophilicity than does the hydrophobic first block.

A person skilled in the art will appreciate that the flexible fuelvehicle may be fuelled with gasoline typically containing 5 wt % to 85wt %, or 10 wt % up to 85 wt %, or 15 wt % to up to 85 wt % alcohol. Thealcohol may for instance be ethanol.

The hydrophobic first block may contain 0 wt % to 5 wt % of ahydrophilic monomer (i.e., units derived from a monomer with a polargroup such as a monomer containing a heteroatom group derived from anitrogen or oxygen containing group. Monomers of this type are discussedin more detail below. In one embodiment the hydrophobic first block maycontain 0 wt % a hydrophilic monomer.

In one embodiment the invention provides a method of lubricating aninternal combustion engine comprising supplying to the engine alubricating composition comprising an oil of lubricating viscosity and ablock copolymer, wherein the block copolymer comprises:

-   -   (a) a hydrophobic first block having C₁₋₃₀ alkyl (meth)acrylic        units, wherein at least 50 wt % of the C₁₋₃₀ alkyl (meth)acrylic        units are C₁₂₋₁₅ alkyl (meth)acrylic units, and up to 50 wt % of        the C₁₋₃₀ alkyl (meth)acrylic units are C₁₆₋₂₀ alkyl        (meth)acrylic units, with the proviso that alkyl groups of the        C₁₋₃₀ alkyl (meth)acrylic units have an average total number of        carbon atoms of at least 8; and    -   (b) a second block having (meth)acrylic units which further have        a non-carbonyl heteroatom-containing group providing a polar        group to such units, whereby said second block exhibits greater        hydrophilicity than does the hydrophobic first block.

In one embodiment the invention provides for the use of a blockcopolymer comprising:

-   -   (a) a hydrophobic first block having C₁₋₃₀ alkyl (meth)acrylic        units, with the proviso that alkyl groups of the C₁₋₃₀ alkyl        (meth)acrylic units have an average total number of carbon atoms        of at least 8; and    -   (b) a second block having (meth)acrylic units which further have        a non-carbonyl heteroatom-containing group providing a polar        group to such units, whereby said second block exhibits greater        hydrophilicity than does the hydrophobic first block providing a        polar group such that the block copolymer may be an emulsifier        and/or pour point depressant.

In one embodiment the invention provides for the use of a blockcopolymer comprising:

-   -   (a) a hydrophobic first block having C₁₋₃₀ alkyl (meth)acrylic        units, wherein at least 50 wt % of the C₁₋₃₀ alkyl (meth)acrylic        units are C₁₂₋₁₅ alkyl (meth)acrylic units, and up to 50 wt % of        the C₁₋₃₀ alkyl (meth)acrylic units are C₁₆₋₂₀ alkyl        (meth)acrylic units, with the proviso that alkyl groups of the        C₁₋₃₀ alkyl (meth)acrylic units have an average total number of        carbon atoms of at least 8; and    -   (b) a second block having (meth)acrylic units which further have        a non-carbonyl heteroatom-containing group providing a polar        group to such units, whereby said second block exhibits greater        hydrophilicity than does the hydrophobic first block such that        the block copolymer may be an emulsifier and/or pour point        depressant.

Typically the block copolymer may be an emulsifier and/or pour pointdepressant in an internal combustion engine.

Pour point depressant properties typically occur when the blockcopolymer contains C₁₆₋₂₀ alkyl (meth)acrylic units.

Emulsifier properties may occur for any block copolymer composition ofthe present invention.

Emulsifier and pour point depressant properties typically occur when thediblock block copolymer contains C₁₆₋₂₀ alkyl (meth)acrylic units, andC₁₂₋₁₅ alkyl (meth)acrylic units.

The internal combustion engine may be operated on gasoline, diesel,biofuels, ethanol, or mixtures thereof. In one embodiment the internalcombustion engine may be operated on a mixture of gasoline and ethanol.The internal combustion engine may be referred to as a flexible fuelvehicle engine.

Typically the block copolymer disclosed herein may be a linear diblockcopolymer.

In one embodiment the lubricating composition may be furthercharacterised as having at least one of (i) a sulphur content of 0.8 wt% or less, (ii) a phosphorus content of 0.2 wt % or less, or (iii) asulphated ash content of 2 wt % or less.

In one embodiment the lubricating composition may be furthercharacterised as having (i) a sulphur content of 0.5 wt % or less, (ii)a phosphorus content of 0.1 wt % or less, and (iii) a sulphated ashcontent of 1.5 wt % or less.

In one embodiment the lubricating composition further includes at leastone of a friction modifier, a viscosity modifier, an antioxidant, anoverbased detergent, a succinimide dispersant, a pour point depressant,or mixtures thereof.

In one embodiment the lubricating composition further includes aviscosity modifier and an overbased detergent.

In one embodiment the lubricating composition further includes anoverbased detergent and a succinimide dispersant.

In one embodiment the invention provides a method for lubricating anengine oil comprising supplying to the engine a lubricating compositionas disclosed herein.

The block copolymer may be used at 0.01 wt % to 0.5 wt %, or 0.05 to 0.3wt % of the lubricating composition disclosed herein.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides a lubricating composition and a methodfor lubricating a mechanical device as disclosed above. Typically themechanical device may be an internal combustion engine.

Block Copolymer

As used herein the term “(meth)acrylic units” includes both acrylic andmethacrylic units and the units are derived from an appropriate monomer.The (meth)acrylic units typically include methacrylates, acrylates,methacrylamides, acrylamides, or mixtures thereof.

As described hereinafter the molecular weight of the block copolymer hasbeen determined using known methods, such as GPC analysis usingpolystyrene standards. Methods for determining molecular weights ofpolymers are well known. The methods are described for instance: (i) P.J. Flory, “Principles of Polymer Chemistry”, Cornell University Press91953), Chapter VII, pp 266-315; or (ii) “Macromolecules, anIntroduction to Polymer Science”, F. A. Bovey and F. H. Winslow,Editors, Academic Press (1979), pp 296-312.

The block copolymer may be a diblock, a triblock, or a higher blockcopolymer.

The diblock copolymer may have a AB composition, where A is ahydrophobic unit, and B is a hydrophilic unit.

The triblock copolymer may have ABA or BAB, ABA′, or BAB′, where A and Bare defined above, and A′ and B′ represent hydrophobic and hydrophilicunits different from A and B respectively.

Each block may be a tapered copolymer, a random copolymer, a sequentialcopolymer, or may have a random or sequential distribution of two ormore monomer units.

The weight average molecular weight of the block copolymer may be in therange of 1000 to 400,000, or 1000 to 150,000, or 15,000 to 100,000.

The weight ratio of the second block to the first block may be in therange of 1:2 to 1:100, or 1:4 to 1:30, or 1:6 to 1:18.

The length of the first block to the second block may have a ratio of10:1 to 1:10, or 6:1 to 1:2.

The C₁₋₃₀ alkyl (meth)acrylic units may be derived from an alkyl(meth)acrylate.

The alkyl (meth)acrylate includes for example compounds derived fromsaturated alcohols, such as methyl methacrylate, butyl methacrylate,2-methylpentyl (meth)acrylate, 2-propylheptyl (meth)acrylate,2-butyloctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, octyl(meth)acrylate, nonyl (meth)acrylate, isooctyl (meth)acrylate, isononyl(meth)acrylate, 2-tert-butyl-heptyl (meth)acrylate, 3-isopropylheptyl(meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate,5-methylundecyl (meth)acrylate, dodecyl (meth)-acrylate, 2-methyldodecyl(meth)acrylate, tridecyl (meth)acrylate, 5-methyl-tridecyl(meth)acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate,hexadecyl (meth)acrylate, 2-methylhexadecyl (meth)acrylate, heptadecyl(meth)acrylate, 5-isopropylheptadecyl (meth)acrylate,4-tert-butyloctadecyl (meth)acryl ate, 5-ethyloctadecyl (meth)acrylate,3-isopropyl octadecyl-(meth)acryl ate, octadecyl (meth)acrylate,nonadecyl (meth)acrylate, eicosyl (meth)acrylate, cetyleicosyl(meth)acrylate, stearyleicosyl (meth)acrylate, docosyl (meth)acrylateand/or eicosyltetratriacontyl (meth)acrylate; (meth)-acrylates derivedfrom unsaturated alcohols, such as oleyl (meth)acrylate; and cycloalkyl(meth)acrylates, such as 3-vinyl-2-butylcyclohexyl (meth)acrylate orbornyl (meth)acrylate.

The alkyl (meth)acrylates with long-chain alcohol-derived groups may beobtained, for example, by reaction of a (meth)acrylic acid (by directesterification) or methyl methacrylate (by transesterification) withlong-chain fatty alcohols, in which reaction a mixture of esters such as(meth)acrylate with alcohol groups of various chain lengths is generallyobtained. These fatty alcohols include Oxo Alcohol® 7911, Oxo Alcohol®7900 and Oxo Alcohol® 1100 of Monsanto; Alphanol® 79 of ICI; Nafol®1620, Alfol® 610 and Alfol® 810 of Condea (now Sasol); Epal® 610 andEpal® 810 of Ethyl Corporation; Linevol® 79, Linevol® 911 and Dobanol®25 L of Shell AG; Lial® 125 of Condea Augusta, Milan; Dehydad® andLorol® of Henkel KGaA (now Cognis) as well as Linopol® 7-11 and Acropol®91 of Ugine Kuhlmann.

In one embodiment the block copolymer may be a methacrylate polymer.

The hydrophobic first block may contain 70 wt % or more, or 80 wt % ormore of the C₁₋₃₀ alkyl (meth)acrylic units containing C₁₂₋₁₅ alkyl(meth)acrylic units.

The hydrophobic first block may contain up to 30 wt %, or up to 20 wt %of the C₁₋₃₀ alkyl (meth)acrylic units containing C₁₆₋₂₀ alkyl(meth)acrylic units.

In one embodiment the hydrophobic first block contains C₁₋₃₀ alkyl(meth)acrylic units, wherein at least 70 wt % of the C₁₋₃₀ alkyl(meth)acrylic units may be C₁₂₋₁₅ alkyl (meth)acrylic units, and up to30 wt % of the C₁₋₃₀ alkyl (meth)acrylic units are C₁₆₋₂₀ alkyl(meth)acrylic units, with the proviso that alkyl groups of the C₁₋₃₀alkyl (meth)acrylic units have an average total number of carbon atomsof at least 8 (or at least 10 carbon atoms).

In one embodiment the hydrophobic first block contains C₁₋₃₀ alkyl(meth)acrylic units, wherein at least 80 wt % of the C₁₋₃₀ alkyl(meth)acrylic units may be C₁₂₋₁₅ alkyl (meth)acrylic units, and up to20 wt % of the C₁₋₃₀ alkyl (meth)acrylic units are C₁₆₋₂₀ alkyl(meth)acrylic units, with the proviso that alkyl groups of the C₁₋₃₀alkyl (meth)acrylic units have an average total number of carbon atomsof at least 8 (or at least 10 carbon atoms).

In one embodiment the hydrophobic first block contains C₁₋₃₀ alkyl(meth)acrylic units, wherein at least 50 wt % to 99 wt % of the C₁₋₃₀alkyl (meth)acrylic units are C₁₂₋₁₅ alkyl (meth)acrylic units, and 1 upto 50 wt % of the C₁₋₃₀ alkyl (meth)acrylic units are C₁₆₋₂₀ alkyl(meth)acrylic units, with the proviso that alkyl groups of the C₁₋₃₀alkyl (meth)acrylic units have an average total number of carbon atomsof at least 8 (or at least 10 carbon atoms).

In one embodiment the hydrophobic first block contains C₁₋₃₀ alkyl(meth)acrylic units, wherein at least 75 wt % to 95 wt % of the C₁₋₃₀alkyl (meth)acrylic units are C₁₂₋₁₅ alkyl (meth)acrylic units, and 5 upto 25 wt % of the C₁₋₃₀ alkyl (meth)acrylic units are C16-20 alkyl(meth)acrylic units, with the proviso that alkyl groups of the C₁₋₃₀alkyl (meth)acrylic units have an average total number of carbon atomsof at least 8 (or at least 10 carbon atoms).

In one embodiment the hydrophobic first block contains C₁₋₃₀ alkyl(meth)acrylic units, wherein at least 80 wt % to 95 wt % of the C₁₋₃₀alkyl (meth)acrylic units are C₁₂₋₁₅ alkyl (meth)acrylic units, and 1 upto 20 wt % of the C₁₋₃₀ alkyl (meth)acrylic units are C₁₆₋₂₀ alkyl(meth)acrylic units, with the proviso that alkyl groups of the C₁₋₃₀alkyl (meth)acrylic units have an average total number of carbon atomsof at least 8 (or at least 10 carbon atoms).

The second block having (meth)acrylic units have a heteroatom-containinggroup providing the polar group, with the heteroatom including sulphur,nitrogen, non-carbonyl oxygen, phosphorus, or mixtures thereof. In oneembodiment the heteroatom may be nitrogen. The term “non-carbonyloxygen” is not meant to exclude the presence of a carbonyl oxygen, butrather to indicate that if such is present, there will also be aheteroatom that is not a carbonyl oxygen (that is, neither an oxygenatom of an aldehyde, ketone or either oxygen atoms of a carboxylic acidor ester).

In one embodiment the copolymer of the invention further includes aheteratom group derived from a nitrogen or oxygen containing group. Thegroup may be derived from a nitrogen or oxygen containing compoundcapable of being incorporated during copolymerisation.

The nitrogen or oxygen containing group may be derived from anaminoalkyl (meth)acrylamide or a nitrogen containing (meth)acrylatemonomer that may be represented by the formula:

wherein

-   -   Q is hydrogen or methyl and, in one embodiment, Q is methyl;    -   Z is an N—H group or an NR² group or O (oxygen);    -   each R² is independently hydrogen or a hydrocarbyl group        containing 1 to 8, or 1 to 4 carbon atoms;    -   each R¹ is independently hydrogen or a hydrocarbyl group        containing 1 to 2 carbon atoms and, in one embodiment, each R¹        is hydrogen; and    -   g is an integer in ranges including 1 to 6, or 1 to 3.

Examples of suitable nitrogen-containing compounds capable of beingincorporated into the copolymer include N,N-dimethylacrylamide, N-vinylcarbonamides (such as, N-vinyl-formamide, N-vinylacetoamide, N-vinylpropionamides, N-vinyl hydroxyacetoamide, vinyl pyridine, N-vinylimidazole, N-vinyl pyrrolidinone, N-vinyl caprolactam,dimethylaminoethyl acryl ate, dimethyl aminoethyl methacrylate, dimethylaminobutyl acrylamide, dimethylaminopropyl methacrylate,dimethylaminopropyl acrylate, dimethyl-aminopropylacrylamide,dimethylaminopropylmethacrylamide, dimethylamino-ethylacrylamide ormixtures thereof.

In one embodiment the heteratom group derived from a nitrogen containinggroup may include dimethylaminoethyl acrylate, dimethyl-aminoethylmethacrylate, dimethylaminopropyl methacrylate, dimethylamino-propylacrylate, dimethylaminopropylacrylamide,dimethylaminopropyl-methacrylamide, nitriles of (meth)acrylic acid andother nitrogen-containing (meth)acrylates, such asN-(methacryloyloxyethyl)diisobutyl ketimine,N-(methacryloyloxyethyl)dihexadecyl ketimine,methacryloylamidoacetonitrile, 2-methacryloyloxyethylmethylcyanamide,cyanomethyl methacrylate, or mixtures thereof.

Examples of suitable non-carbonyl oxygen containing compounds capable ofbeing incorporated into the copolymer include hydroxyalkyl(meth)acrylates such as 3-hydroxypropyl methacrylate, 3,4-dihydroxybutylmethacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate,2,5-dimethyl-1,6-hexanediol (meth)acrylate, 1,10-decanediol(meth)acrylate, carbonyl-containing methacrylates such as 2-carboxyethylmethacrylate, carboxymethyl methacrylate, oxazolidinyl ethylmethacrylate, N-(methacryloyl-oxy)formamide, acetonyl methacrylate,N-methacryloylmorpholine, N-methacryloyl-2-pyrrolidinone,N-(2-methacryloyloxyethyl)-2-pyrrolidinone, N-(3-methacryloyloxypropyl)-2-pyrrolidinone, N-(2-methacryloyloxypentadecyl)-2-pyrrolidinone, N-(3-methacryloyloxyheptadecyl)-2-pyrrolidinone; glycol dimethacrylates such as1,4-butanediol methacrylate, 2-butoxyethyl methacryl ate,2-ethoxyethoxym ethyl methacrylate, 2-ethoxyethyl methacryl ate, ormixtures thereof.

Other examples of suitable non-carbonyl oxygen containing compoundscapable of being incorporated into the copolymer include methacrylatesof ether alcohols, such as tetrahydrofurfuryl methacrylate, vinyloxyethoxyethyl methacrylate, methoxyethoxyethyl methacrylate,1-butoxypropyl methacrylate, 1-methyl-(2-vinyloxy)ethyl methacrylate,cyclo-hexyloxymethyl methacrylate, methoxymethoxyethyl methacrylate,benzyl oxy-methyl methacrylate, furfuryl methacrylate, 2-butoxyethylmethacrylate, 2-ethoxyethoxym ethyl methacryl ate, 2 -ethoxyethylmethacrylate, allyloxymethyl methacrylate, 1-ethoxybutyl methacrylate,methoxymethyl methacrylate, 1-ethoxyethyl methacrylate, ethoxymethylmethacrylate and ethoxylated (meth)-acrylates which typically have 1 to20, or 2 to 8, ethoxy groups, or mixtures thereof.

The block copolymer may be obtained/obtainable from controlled radicalor other living polymerisation techniques such as RAFT (ReversibleAddition Fragmentation Transfer), ATRP (Atom Transfer RadicalPolymerisation), nitroxide-mediated and anionic. These polymerisationtechniques are known to a person skilled in the art.

Anionic polymerisation processes may be useful when the heteroatom ofthe second block contains a nitrogen heteroatom (from an amine) whensteps are taken to quench the amine during polymerisation. Suchtechniques are known to a person skilled in the art.

More detailed descriptions of polymerisation mechanisms and relatedchemistry is discussed for nitroxide-mediated polymerisation (Chapter10, pages 463 to 522) of in the Handbook of Radical Polymerization,edited by Krzysztof Matyjaszewski and Thomas P. Davis, 2002, publishedby John Wiley and Sons Inc (hereinafter referred to as “Matyjaszewski etal.”).

In one embodiment the controlled radical polymerisation process employedto prepare the block copolymer may be a RAFT process. A detaileddescription of RAFT processes is described in WO2006/047393 (see wholedocument for reagents, and reference to linear polymers) or US PatentApplication 2006/0189490 (see paragraphs [0128] to [0131].

In one embodiment the controlled radical polymerisation process employedto prepare the block copolymer may be an ATRP process. In ATRPpolymerisation, groups that may be transferred by a radical mechanisminclude halogens (from a halogen-containing compound) or variousligands. A more detailed review of groups that may be transferred isdescribed in U.S. Pat. No. 6,391,996, or paragraphs 61 to 65 of USPatent Application 2005/038146. Another detailed description of ATRPprocesses is described in US Patent Application 2006/0189490 (seeparagraphs [0102] to [0126]).

More detailed descriptions of polymerisation mechanisms and relatedchemistry is discussed for ATRP (Chapter 11, pages 523 to 628) and RAFT(Chapter 12, pages 629 to 690) in Matyjaszewski et al.

In one embodiment the controlled radical polymerisation process may be aRAFT process.

In RAFT polymerisation, chain transfer agents are important. A moredetailed review of suitable chain transfer agents is found in paragraphs66 to 71 of US Patent Application US 2005/038146.

In one embodiment a suitable RAFT chain transfer agent includes2-Dodecylsulphanylthiocarbonyl sulphanyl-2-methyl-propionic acid butylester, cumyl dithiobenzoate or mixtures thereof.

Oils of Lubricating Viscosity

The lubricating composition comprises an oil of lubricating viscosity.Such oils include natural and synthetic oils, oil derived fromhydrocracking, hydrogenation, and hydrofinishing, unrefined, refined andre-refined oils and mixtures thereof.

Unrefined oils are those obtained directly from a natural or syntheticsource generally without (or with little) further purificationtreatment.

Refined oils are similar to the unrefined oils except they have beenfurther treated in one or more purification steps to improve one or moreproperties. Purification techniques are known in the art and includesolvent extraction, secondary distillation, acid or base extraction,filtration, percolation and the like.

Re-refined oils are also known as reclaimed or reprocessed oils, and areobtained by processes similar to those used to obtain refined oils andoften are additionally processed by techniques directed to removal ofspent additives and oil breakdown products.

Natural oils useful in making the inventive lubricants include animaloils, vegetable oils (e.g., castor oil), mineral lubricating oils suchas liquid petroleum oils and solvent-treated or acid-treated minerallubricating oils of the paraffinic, naphthenic or mixedparaffinic-naphthenic types and oils derived from coal or shale ormixtures thereof.

Synthetic lubricating oils are useful and include hydrocarbon oils suchas polymerised and interpolymerised olefins (typically hydrogenated)(e.g., polybutylenes, polypropylenes, propyleneisobutylene copolymers);poly(1-hexenes), poly(1-octenes), poly(1-decenes), and mixtures thereof;alkyl-benzenes (e.g. dodecylbenzenes, tetradecylbenzenes,dinonylbenzenes, di-(2-ethylhexyl)-benzenes); polyphenyls (e.g.,biphenyls, terphenyls, alkylated polyphenyls); diphenyl alkanes,alkylated diphenyl alkanes, alkylated diphenyl ethers and alkylateddiphenyl sulphides and the derivatives, analogs and homologs thereof ormixtures thereof.

Other synthetic lubricating oils include polyol esters (such asProlube®3970), diesters, liquid esters of phosphorus-containing acids(e.g., tricresyl phosphate, trioctyl phosphate, and the diethyl ester ofdecane phosphonic acid), or polymeric tetrahydrofurans. Synthetic oilsmay be produced by Fischer-Tropsch reactions and typically may behydroisomerised Fischer-Tropsch hydrocarbons or waxes. In one embodimentoils may be prepared by a Fischer-Tropsch gas-to-liquid syntheticprocedure as well as other gas-to-liquid oils.

Oils of lubricating viscosity may also be defined as specified in theAmerican Petroleum Institute (API) Base Oil InterchangeabilityGuidelines. The five base oil groups are as follows: Group I (sulphurcontent >0.03 wt %, and/or ≦90 wt % saturates, viscosity index 80-120);Group II (sulphur content ≦0.03 wt %, and ≧90 wt % saturates, viscosityindex 80-120); Group III (sulphur content ≦0.03 wt %, and ≧90 wt %saturates, viscosity index ≧120); Group IV (all polyalphaolefins(PAOs)); and Group V (all others not included in Groups I, II, III, orIV). The oil of lubricating viscosity includes an API Group I, Group II,Group III, Group IV, Group V oil or mixtures thereof. Often the oil oflubricating viscosity is an API Group I, Group II, Group III, Group IVoil or mixtures thereof.

The amount of the oil of lubricating viscosity present is typically thebalance remaining after subtracting from 100 wt % the sum of the amountof the compound of the invention and the other performance additives.

The lubricating composition may be in the form of a concentrate and/or afully formulated lubricant. If the lubricating composition of theinvention comprising the additives disclosed herein above is in the formof a concentrate (which may be combined with additional oil to form, inwhole or in part, a finished lubricant), the ratio of the of theseadditives to the oil of lubricating viscosity and/or to diluent oilinclude the ranges of 1:99 to 99:1 by weight, or 80:20 to 10:90 byweight.

Other Performance Additives

The composition optionally includes other performance additives. Theother performance additives comprise at least one of metal deactivators,viscosity modifiers, detergents, friction modifiers, antiwear agents,corrosion inhibitors, dispersants, dispersant viscosity modifiers,extreme pressure agents, antioxidants, foam inhibitors, demulsifiers,emulsifiers (other than the block copolymer of the invention), pourpoint depressants (other than the block copolymer of the invention),seal swelling agents and mixtures thereof. Typically, fully-formulatedlubricating oil will contain one or more of these performance additives.

In one embodiment the lubricating composition of the invention furtherincludes at least one of a friction modifier, a viscosity modifier, anantioxidant, an overbased detergent, a succinimide dispersant, ormixtures thereof.

In one embodiment the lubricating composition of the invention furtherincludes at least one of a viscosity modifier, an antioxidant, anoverbased detergent, a succinimide dispersant, or mixtures thereof.

Detergents

In one embodiment the lubricating composition further includes knownneutral or overbased detergents. Suitable detergent substrates includephenates, sulphur containing phenates, sulphonates, salixarates,salicylates, carboxylic acid, phosphorus acid, mono- and/ordi-thiophosphoric acids, alkyl phenols, sulphur coupled alkyl phenolcompounds, or saligenins. Various overbased detergents and their methodsof preparation are described in greater detail in numerous patentpublications, including WO2004/096957 and references cited therein. Thedetergent substrate may be salted with a metal such as calcium,magnesium, potassium, sodium, or mixtures thereof.

In one embodiment the overbased detergent is selected from the groupconsisting of phenates, sulphur containing phenates, sulphonates,salixarates, salicylates, and mixtures thereof. Typically the selectedoverbased detergent include calcium or magnesium phenates, sulphurcontaining phenates, sulphonates, salixarates, saliginens, salicylates,or mixtures thereof.

In one embodiment the detergent may be a calcium salicylate. In oneembodiment the detergent may be a calcium sulphonate. In one embodimentthe invention the detergent may be a mixture of a calcium sulphonate anda calcium salicylate.

In one embodiment the detergent may be a calcium phenate. In oneembodiment the detergent may be a calcium sulphonate. In one embodimentthe invention the detergent may be a mixture of a calcium sulphonate anda calcium phenate.

When the lubricating composition is not lubricating a 2-stroke marinediesel engine the detergent may be present (on an oil free basis i.e.,an actives basis) at 0 wt % to 10 wt %, or 0.1 wt % to 8 wt %, or 1 wt %to 4 wt % of the lubricating composition. When the lubricatingcomposition is lubricating a 2-stroke marine diesel engine the amount ofdetergent (on an oil free basis i.e., an actives basis)may be 0 wt % to40 wt %, or 2 wt % to 35 wt %, or 5 wt % to 30 wt % of the lubricatingcomposition.

Dispersants

Dispersants are often known as ashless-type dispersants because, priorto mixing in a lubricating oil composition, they do not containash-forming metals and they do not normally contribute any ash formingmetals when added to a lubricant and polymeric dispersants. Ashless typedispersants are characterised by a polar group attached to a relativelyhigh molecular weight hydrocarbon chain. Typical ashless dispersantsinclude N-substituted long chain alkenyl succinimides. Examples ofN-substituted long chain alkenyl succinimides include polyisobutylenesuccinimide with number average molecular weight of the polyisobutylenesubstituent in the range 350 to 5000, or 500 to 3000. Succinimidedispersants and their preparation are disclosed, for instance in U.S.Pat. No. 3,172,892 or U.S. Pat. No. 4,234,435. Succinimide dispersantsare typically the imide formed from a polyamine, typically apoly(ethyleneamine).

In one embodiment the invention further includes at least one dispersantwhich is a polyisobutylene succinimide derived from a polyisobutylenewith number average molecular weight in the range 350 to 5000, or 500 to3000. The polyisobutylene succinimide may be used alone or incombination with other dispersants.

In one embodiment the invention further includes at least one dispersantderived from polyisobutylene succinic anhydride, an amine and zinc oxideto form a polyisobutylene succinimide complex with zinc. Thepolyisobutylene succinimide complex with zinc may be used alone or incombination.

Another class of ashless dispersant includes Mannich bases. Mannichdispersants are the reaction products of alkyl phenols with aldehydes(especially formaldehyde) and amines (especially polyalkylenepolyamines). The alkyl group typically contains at least 30 carbonatoms.

The dispersants may also be post-treated by conventional methods by areaction with any of a variety of agents. Among these are boron, urea,thiourea, dimercaptothiadiazoles, carbon disulphide, aldehydes, ketones,carboxylic acids, hydrocarbon-substituted succinic anhydrides, maleicanhydride, nitriles, epoxides, and phosphorus compounds.

The dispersant (typically a polyisobutylene succinimide) may have a hightotal base number or the dispersant may have a high total acid number.Generally dispersants with a high TAN number have a carbonyl to nitrogenratio of 1 or higher, in one aspect 1.2 or higher, in another aspect 1.4or higher and in yet another aspect 1.45 or higher, for example 1.5.Generally dispersants with a high TBN number have a carbonyl to nitrogenratio of less than 1, in one aspect 0.94 or lower, in another aspect0.88 or lower and in another aspect 0.8 or lower, for instance 0.77. Thecarbonyl to nitrogen ratio is to be calculated on a molar basis, thatis, the ratio of moles of carbonyl functionality (e.g., —C(O)O—) to themoles of nitrogen functionality (e.g., amine nitrogens). In oneembodiment the dispersant may be in a mixture of (i) a dispersant with acarbonyl to nitrogen ratio of 1 or higher; and (ii) a dispersant with acarbonyl to nitrogen ratio of less than 1.

The dispersant may be present (on an oil free basis i.e., an activesbasis) at 0 wt % to 20 wt %, or 0.1 wt % to 15 wt %, or 0.1 wt % to 10wt %, or 1 wt % to 6 wt % of the lubricating composition.

Antioxidants

Antioxidant compounds are known and include for example, sulphurisedolefins, alkylated diphenylamines (typically di-nonyl diphenyl amine,octyl diphenyl amine, di-octyl diphenylamine), hindered phenols,molybdenum compounds (such as molybdenum dithiocarbamates), or mixturesthereof. Antioxidant compounds may be used alone or in combination. Theantioxidant may be present in ranges (on an oil free basis i.e., anactives basis) of 0 wt % to 20 wt %, or 0.1 wt % to 10 wt %, or 1 wt %to 5 wt %, of the lubricating composition.

The hindered phenol antioxidant often contains a secondary butyl and/ora tertiary butyl group as a sterically hindering group. The phenol groupmay be further substituted with a hydrocarbyl group (typically linear orbranched alkyl) and/or a bridging group linking to a second aromaticgroup.

Examples of suitable hindered phenol antioxidants include2,6-di-tert-butylphenol, 4-methyl-2,6-di-tert-butylphenol,4-ethyl-2,6-di-tert-butylphenol, 4-propyl-2,6-di-tert-butylphenol or4-butyl-2,6-di-tert-butylphenol, or 4-dodecyl-2,6-di-tert-butylphenol.In one embodiment the hindered phenol antioxidant may be an ester andmay include, e.g., Irganox™ L-135 from Ciba. A more detailed descriptionof suitable ester-containing hindered phenol antioxidant chemistry isfound in U.S. Pat. No. 6,559,105.

In one embodiment the lubricating composition further includes amolybdenum compound.

The molybdenum compound is selected from the group consisting ofmolybdenum di alkyl dithiophosphates, molybdenum dithiocarbamates, aminesalts of molybdenum compounds, and mixtures thereof.

Suitable examples of molybdenum dithiocarbamates which may be used as anantioxidant include commercial materials sold under the trade names suchas Molyvan 822™, Molyvan™ A and Molyvan 855™ from R. T. Vanderbilt Co.,Ltd., and Adeka Sakura-Lube™ S-100, S-165 S-515, S-600 and S-710 fromAdeka ; and mixtures thereof.

When present, the molybdenum compound may provide 5 ppm to 1000 ppm, or20 ppm to 300 ppm of molybdenum to the lubricating composition.

Viscosity Modifiers

Viscosity modifiers include hydrogenated copolymers of maleicanhydride-(alpha olefin) copolymers, styrene-butadiene,ethylene-propylene copolymers, polyisobutenes, hydrogenatedstyrene-isoprene polymers, hydrogenated isoprene polymers,polymethacrylates, polyacrylates, polyalkyl styrenes, hydrogenatedalkenyl arene conjugated diene copolymers, polyolefins, esters of maleicanhydride-styrene copolymers.

Dispersant Viscosity Modifiers

Dispersant viscosity modifiers (often referred to as DVM), includefunctionalised polyolefins, for example, ethylene-propylene copolymersthat have been functionalized with an acylating agent such as maleicanhydride and an amine; polymethacrylates functionalised with an amine,or esterified styrene-maleic anhydride copolymers reacted with an amine.

Antiwear Agents

In one embodiment the lubricating composition further includes anantiwear agent.

The additional antiwear agent may be either ashless or ash-forming.Typically ashless antiwear agents do not contain metal, whereasash-forming do contain metal.

The antiwear agent may be present (on an oil free basis i.e., an activesbasis) in ranges including 0 wt % to 15 wt %, or 0 wt % to 10 wt %, or0.05 wt % to 5 wt %, or 0.1 wt % to 3 wt % of the lubricatingcomposition.

In one embodiment the lubricating composition further includes aphosphorus-containing antiwear agent. Typically thephosphorus-containing antiwear agent may be present in an amount todeliver the ranges of phosphorus described below in the subject matterunder the sub-heading “Industrial Application”.

Examples of suitable antiwear agents include phosphate esters,sulphurised olefins, sulphur-containing anti-wear additives includingmetal dihydrocarbyldithiophosphates (such as primary or secondary zincdialkyldithiophosphates, or molybdenum di alkyl dithiophosphates),molybdenum thiocarbamate-containing compounds including thiocarbamateesters, alkylene-coupled thiocarbamates, and bis(S-alkyldithiocarbamyl)disulphides.

Examples of suitable zinc dialkyldithiophosphates include thosedisclosed in PCT Application US07/073428 (entitled “Method ofLubricating an Internal Combustion Engine and Improving the Efficiencyof the Emissions Control System of the Engine”) or in PCT ApplicationUS07/073426 (entitled “Lubricating Oil Composition and Method ofImproving Efficiency of Emissions Control System”). Both applicationsclaim priority from Jul. 17, 2006. The zinc dialkyldithiophosphates orzinc dialkylphosphates may in one embodiment be defined as a zinc saltof a mixture of phosphorus-containing compounds represented by theformula:

wherein in formula, J¹ and J² are independently S or O, and R³ and R⁴may be independently hydrocarbyl groups, the average total number ofcarbon atoms in R³ plus R⁴ for the mixture of phosphorus-containingcompounds being at least 9.5; wherein R³ and R⁴ are characterised inthat (i) 4 to 70 mole percent of such groups contain 2 to 4 carbon atomsand (ii) 30 to 96 mole percent such groups contain 5 to 12 carbon atoms;and wherein, in less than 8 mole percent of the molecules of the formulain the mixture of phosphorus-containing compounds, each of R³ and R⁴contain 2 to 4 carbon atoms and in greater than 11 mole percent of themolecules of the formula in said mixture R³ has 2 to 4 carbon atoms andR⁴ has 5 to 12 carbon atoms; and wherein, within the formula, theaverage total number of hydrogen atoms in R³ and R⁴ on carbon atomslocated beta to the O atoms is at least 7.25.

The dithiocarbamate-containing compounds may be prepared by reacting adithiocarbamate acid or salt with an unsaturated compound. Thedithiocarbamate containing compounds may also be prepared bysimultaneously reacting an amine, carbon disulphide and an unsaturatedcompound. Generally, the reaction occurs at a temperature of 25° C. to125° C. U.S. Pat. Nos. 4,758,362 and 4,997,969 describe dithiocarbamatecompounds and methods of making them.

Examples of suitable olefins that may be sulphurised to form ansulphurised olefin include propylene, butylene, isobutylene, pentene,hexane, heptene, octane, nonene, decene, undecene, dodecene, undecyl,tridecene, tetradecene, pentadecene, hexadecene, heptadecene,octadecene, octadecenene, nonodecene, eicosene or mixtures thereof. Inone embodiment, hexadecene, heptadecene, octadecene, octadecenene,nonodecene, eicosene or mixtures thereof and their dimers, trimers andtetramers are especially useful olefins. Alternatively, the olefin maybe a Diels-Alder adduct of a diene such as 1,3-butadiene and anunsaturated ester, such as butylacrylate.

Another class of sulphurised olefin includes fatty acids and theiresters. The fatty acids are often obtained from vegetable oil or animaloil and typically contain 4 to 22 carbon atoms. Examples of suitablefatty acids and their esters include triglycerides, oleic acid, linoleicacid, palmitoleic acid or mixtures thereof. Often, the fatty acids areobtained from lard oil, tall oil, peanut oil, soybean oil, cottonseedoil, sunflower seed oil or mixtures thereof. In one embodiment fattyacids and/or ester are mixed with olefins.

Extreme Pressure Agents

Extreme Pressure (EP) agents that are soluble in the oil includesulphur- and chlorosulphur-containing EP agents, chlorinated hydrocarbonEP agents and phosphorus EP agents. Examples of such EP agents includechlorinated wax; organic sulphides and polysulphides such as dibenzyldisulphide, bis-(chlorobenzyl) disulphide, dibutyl tetrasulphide,sulphurised methyl ester of oleic acid, sulphurised alkylphenol,sulphurised dipentene, sulphurised terpene, and sulphurised Diels-Alderadducts; phosphosulphurised hydrocarbons such as the reaction product ofphosphorus sulphide with turpentine or methyl oleate; phosphorus esterssuch as the dihydrocarbon and trihydrocarbon phosphites, e.g., dibutylphosphite, diheptyl phosphite, dicyclohexyl phosphite, pentylphenylphosphite; dipentylphenyl phosphite, dioleyl phosphite, di-2-ethylhexylphosphite, didodecyl phosphite, di C₁₂₋₁₄ alkyl phosphite, tridecylphosphite, distearyl phosphite and polypropylene substituted phenolphosphite; metal thiocarbamates such as zinc dioctyldithio-carbamate andbarium heptylphenol diacid; amine salts of alkyl and dialkyl-phosphoricacids, including, for example, the amine salt of the reaction product ofa dialkyldithiophosphoric acid with propylene oxide; and mixturesthereof.

Friction Modifiers

In one embodiment the lubricating composition further includes afriction modifier, or mixtures thereof. Typically the friction modifiermay be present (on an oil free basis i.e., an actives basis) in rangesincluding 0 wt % to 10 wt %, or 0.05 wt % to 8 wt %, or 0.1 wt % to 4 wt%.

Examples of suitable friction modifiers include long chain fatty acidderivatives of amines, esters, or epoxides; fatty imidazolines such ascondensation products of carboxylic acids and polyalkylene-polyamines;amine salts of alkylphosphoric acids; fatty alkyl tartrates; fatty alkyltartrimides; or fatty alkyl tartramides.

Friction modifiers may also encompass materials such as fatty alkyltartrates; fatty alkyl tartrimides, sulphurised fatty compounds andolefins, molybdenum dialkyldithiophosphates, molybdenumdithiocarbamates, sun-flower oil or monoester of a polyol and analiphatic carboxylic acid (all these friction modifiers may also bedescribed as antioxidants or antiwear agents).

In one embodiment the friction modifier friction modifier is selectedfrom the group consisting of long chain fatty acid derivatives ofamines, esters, or epoxides; fatty alkyl tartrates; fatty alkyltartrimides; and fatty alkyl tartramides.

In one embodiment the friction modifier may be a long chain fatty acidester (previously described above as an ashless antiwear agent). In oneembodiment the long chain fatty acid ester may be a mono-ester, e.g., amonoglyceride, and in one embodiment the long chain fatty acid ester maybe a (tri)glyceride.

Other Additives

Other performance additives such as corrosion inhibitors include thosedescribed in paragraphs 5 to 8 of US Application US05/038319 (filed onOct. 25, 2004 McAtee and Boyer as named inventors), octylamineoctanoate, condensation products of dodecenyl succinic acid or anhydrideand a fatty acid such as oleic acid with a polyamine. In one embodimentthe corrosion inhibitors include the Synalox® corrosion inhibitor. TheSynalox® corrosion inhibitor is typically a homopolymer or copolymer ofpropylene oxide. The Synalox® corrosion inhibitor is described in moredetail in a product brochure with Form No. 118-01453-0702 AMS, publishedby The Dow Chemical Company. The product brochure is entitled “SYNALOXLubricants, High-Performance Polyglycols for Demanding Applications.”

Metal deactivators including derivatives of benzotriazoles (typicallytolyltriazole), dimercaptothiadiazole derivatives, 1,2,4-triazoles,benzimidazoles, 2-alkyldithiobenzimidazoles, or2-alkyldithiobenzothiazoles; foam inhibitors including copolymers ofethyl acrylate and 2-ethylhexylacrylate and optionally vinyl acetate;demulsifiers including trialkyl phosphates, polyethylene glycols,polyethylene oxides, polypropylene oxides and (ethylene oxide-propyleneoxide) polymers; pour point depressants including esters of maleicanhydride-styrene, polymethacrylates, polyacrylates or polyacrylamidesmay be useful. Foam inhibitors that may be useful in the compositions ofthe invention include copolymers of ethyl acrylate and2-ethylhexylacrylate and optionally vinyl acetate; demulsifiersincluding trialkyl phosphates, polyethylene glycols, polyethyleneoxides, polypropylene oxides and (ethylene oxide-propylene oxide)polymers.

Pour point depressants that may be useful in the compositions of theinvention include polyalphaolefins, esters of maleic anhydride-styrenecopolymers, fumarate ester-vinyl acetate copolymers,polyalkyl(meth)acrylates, polyalkylacrylates or polyalkyl acrylamides.

Industrial Application

In one embodiment the mechanical device is an internal combustionengine.

In one embodiment the internal combustion engine may be a diesel fueledengine, a gasoline fueled engine, a natural gas fueled engine or a mixedgasoline/alcohol fueled engine. In one embodiment the internalcombustion engine may be a diesel fueled engine and in one embodiment agasoline fueled engine.

The internal combustion engine may be a 2-stroke or 4-stroke engine.Suitable internal combustion engines include marine diesel engines,aviation piston engines, low-load diesel engines, and automobile andtruck engines.

As used herein the components of the internal combustion engine includeall of the parts of the engine derived from metal lubricated by anengine lubricant. This includes for example, cylinder liners, camshafts,pistons, bearings, oil coolers etc.

In one embodiment the internal combustion engine contains componentsferric (i.e., ferrous) components. The ferric components include Fe,FeO, Fe₃O₄ or other materials containing iron.

In one embodiment the internal combustion engine contains components ofan aluminium-alloy. The aluminium-alloy includes aluminium silicates,aluminium oxides, or other ceramic materials. In one embodiment thealuminium-alloy is an aluminium-silicate surface.

The lubricating composition for an internal combustion engine may besuitable for any engine lubricant irrespective of the sulphur,phosphorus or sulphated ash (ASTM D-874) content. The sulphur content ofthe engine oil lubricant may be 1 wt % or less, or 0.8 wt % or less, or0.5 wt % or less, or 0.3 wt % or less. In one embodiment the sulphurcontent may be in the range of 0.001 wt % to 0.5 wt %, or 0.01 wt % to0.3 wt %. The phosphorus content may be 0.2 wt % or less, or 0.1 wt % orless, or 0.085 wt % or less, or even 0.06 wt % or less, 0.055 wt % orless, or 0.05 wt % or less. In one embodiment the phosphorus content maybe 100 ppm to 1000 ppm, or 200 ppm to 600 ppm. The total sulphated ashcontent may be 2 wt % or less, or 1.5 wt % or less, or 1.1 wt % or less,or 1 wt % or less, or 0.8 wt % or less, or 0.5 wt % or less. In oneembodiment the sulphated ash content may be 0.05 wt % to 0.9 wt %, or0.1 wt % to 0.2 wt % to 0.45 wt %.

In one embodiment the lubricating composition may be an engine oil,wherein the lubricating composition may be characterised as having (i) asulphur content of 0.5 wt % or less, (ii) a phosphorus content of 0.08wt % or less, and (iii) a sulphated ash content of 1.5 wt % or less.

In one embodiment the lubricating composition may be suitable for a2-stroke or a 4-stroke marine diesel internal combustion engine. In oneembodiment the marine diesel combustion engine is a 2-stroke engine.

The block copolymer of the invention may also be used in a variety oflubricants requiring emulsifiers and/or pour point depressants. Theblock copolymer of the invention may be an emulsifier and/or pour pointdepressant in driveline devices, industrial gears, hydraulic devices,off-highway mobile equipment such as farm tractors, greases,metalworking fluids and fuels. For each of these devices the lubricantformulation may, as a person skilled in the art will appreciate, changedue to the different additives and treat rates commonly employed in eachlubricant type. None the less, the block copolymer is believed tofunction as an emulsifier and/or pour point depressant.

Driveline devices include gearboxes, axle gears, traction drivetransmissions, automatic transmissions or manual transmissions.

Automatic transmissions include continuously variable transmissions(CVT), infinitely variable transmissions (IVT), Torroidal transmissions,continuously slipping torque converted clutches (CSTCC), steppedautomatic transmissions or dual clutch transmissions (DCT).

The following examples provide illustrations of the invention. Theseexamples are non-exhaustive and are not intended to limit the scope ofthe invention.

EXAMPLES Preparative Example 1

(EX1) is a diblock copolymer of (C₁₂₋₁₅-alkyl methacrylate and2-ethylhexylmethacrylate)-b-dimethylaminoethyl meth-acrylate. Thediblock copolymer is prepared by charging reagents into a 4-necked flaskequipped with a nitrogen inlet, thermocouple and a heating mantle. Thereagents added include 99.2 g of C₁₂₋₁₅-alkyl methacrylate, 48 g of2-ethylhexylmethacrylate, 5.04 g of a chain transfer agent(dodecyl-trithiocarbonate butyl ester), 0.87 g of Trigonox®21 initiatorand 41.48 g of PAO-4 diluent oil. The flask is stirred and purged withnitrogen for 30 minutes. The nitrogen flow rate is 0.028 m³/hr (or 1SCFH). The flask is then heated to 90° C. and the nitrogen flow isreduced to 0.014 m³/hr (or 0.5 SCFH) and held for 150 minutes. The flaskis then charged with 12.8 g of dimethylaminoethyl methacrylate. Theflask is held for a further 3 hours at 90° C., before cooling. Theproduct is a viscous liquid.

Preparative Example 2

(EX2): is a diblock copolymer of (C₁₂₋₁₅-alkyl methacrylate and2-ethylhexylmethacrylate)-b-dimethylaminoethyl meth-acrylate. 111.6 g ofC₁₂₋₁₅-alkyl methacrylate, 54 g of 2-ethylhexyl-methacrylate, and 0.97 gof Trigonox®21 initiator are blended to form a blend. About one third ofthe blend is charged into a 4-necked flask equipped with a nitrogeninlet, thermocouple and a heating mantle. 5.67 g of a chain transferagent (dodecyl-trithiocarbonate butyl ester) is then added to the flask.

The flask is stirred and purged with nitrogen for 30 minutes. Thenitrogen flow rate is 0.028 m³/hr (or 1 SCFH). The flask is then heatedto 80° C. and the nitrogen flow is reduced to 0.014 m³/hr (or 0.5 SCFH)and the remaining two thirds of the blend is added over a period of 90minutes. The flask is maintained at 80° C. and held for 150 minutes. Theflask is then charged with 14.4 g of dimethylaminoethyl methacrylate.The flask is held for a further 150 minutes at 80° C., before cooling.The product is a viscous liquid.

Preparative Example 3

(EX3): is a diblock copolymer of (C12-15-alkyl methacrylate andC₁₆₋₁₈-alkyl methacrylate)-b-dimethylaminoethyl meth-acrylate. 1500 g ofC₁₂₋₁₅-alkyl methacrylate, 260 g of C₁₆₋₁₈-alkyl meth-acrylate (theC₁₆₋₁₈-alkyl methacrylate also contains up to 5 wt % C₁₄-alkylmethacrylate and up to 2 wt % C₂₀-alkyl methacrylate), and 3 g ofTrigonox®21 initiator are blended to form a blend. About one third ofthe blend is charged into a 4-necked flask equipped with a nitrogeninlet, thermocouple and a heating mantle. 17.5 g of a chain transferagent (dodecyl-trithiocarbonate butyl ester) is then added to the flask.

The flask is stirred and purged with nitrogen for 30 minutes. Thenitrogen flow rate is 0.056 m³/hr (or 2 SCFH). The flask is then heatedto 80° C. and the nitrogen flow is reduced to 0.014 m³/hr (or 0.5 SCFH)and the remaining two thirds of the blend is added over a period of 90minutes. The flask is maintained at 80° C. and held for 15 hours. Theflask is then charged with 240 g of dimethylaminoethyl methacrylate. Theflask is held for at 90° C. for 2 hours. Three separate charges (each 1g) of Trigonox®21 initiator are added over a period of 5 hours. Theproduct is a viscous liquid before dilution with diluent oil to form a40% polymer mixture in oil.

Preparative Example 4

(EX4): is a diblock copolymer prepared by a process similar to EX3,except the final polymer is a block copolymer of (C₁₂₋₁₅-alkylmethacrylate and C₁₆₋₁₈-alkyl methacrylate)-b-(dimethylaminoethylmethacrylate and methylmethacrylate). The methyl methacrylate is addedconcurrently with dimethylaminoethyl methacrylate. The ratio of theweight percent of C₁₂₋₁₅-alkyl methacrylate to C₁₆₋₁₈-alkyl methacrylateis 85:15 (the C₁₆₋₁₈-alkyl methacrylate also contains up to 5 wt %C₁₄-alkyl methacrylate and up to 2 wt % C₂₀-alkyl methacrylate). Theratio of the weight percent of dimethylaminoethyl methacrylate tomethylmethacrylate is 91:9. The ratio weight percent of hydrophobicblock to the second block containing a polar group is 87:13. The productis a viscous liquid before dilution with diluent oil to form a 50%polymer mixture in oil.

Comparative Preparative Example 1

(CP1): is a random polymer of C₁₂₋₁₅-alkyl methacrylate,2-ethylhexylmethacrylate, and dimethylaminoethyl methacrylate. Therandom polymer is prepared by charging reagents into a 4-necked flaskequipped with a nitrogen inlet, thermocouple and a heating mantle. Thereagents added include 99.2 g of C₁₂₋₁₅-alkyl methacrylate, 48 g of2-ethylhexylmethacrylate, 12.8 g of dimethylaminoethyl methacrylate,5.04 g of a chain transfer agent (dodecyl-trithiocarbonate butyl ester),0.87 g of Trigonox®21 initiator and 41.48 g of PAO-4 diluent oil. Theflask is then heated to 90° C. as is described in EX1.

In the following lubricant examples and comparative lubricant examples,the listed amount of the products from the preparative example orcomparative preparative example, as the case may be, includes the amountof diluent oil reported to be added or included therein.

Comparative Lubricant Example 1

(CLC1) is a SAE 5W-30 engine lubricant.

Comparative Lubricant Example 2

(CLC2) is a 5W-30 engine lubricant similar to CLC1, except it furthercontains 0.05 wt % of the product of CP1.

Comparative Lubricant Example 3

(CLC3) is a 5W-30 engine lubricant similar to CLC1, except it furthercontains 0.12 wt % of the product of CP1.

Comparative Lubricant Example 4

(CLC4) is a oil mixture of 80 wt % of ExxonMobil Group II EHCTM-45, withviscosity of 4.6 mm²/s at 100° C. and 20 wt % of ExxonMobil Group IIEHC™-60, with viscosity of 6.0 mm²/s at 100° C.

Lubricant Example 1

(LC1) is a 5W-30 engine lubricant similar to CLC1, except it furthercontains 0.05 wt % of the product of EX1.

Lubricant Example 2

(LC2) is a 5W-30 engine lubricant similar to CLC1, except it furthercontains 0.12 wt % of the product of EX1.

Lubricant Example 3

(LC3) is a 5W-30 engine lubricant similar to CLC1, except it furthercontains 0.05 wt % of the product of EX2.

Lubricant Example 4

(LC4) is a 5W-30 engine lubricant similar to CLC1, except it furthercontains 0.12 wt % of the product of EX2.

Lubricant Example 5

(LC5) is a 5W-30 engine lubricant similar to CLC1, except it furthercontains 0.07 wt % of the product of EX3.

Lubricant Example 6

(LC6) is a 5W-30 engine lubricant similar to CLC1, except it furthercontains 0.16 wt % of the product of EX3.

Lubricant Example 7

(LC7) is a 5W-30 engine lubricant similar to CLC1, except it furthercontains 0.06 wt % of the product of EX4.

Lubricant Example 8

(LC8) is a 5W-30 engine lubricant similar to CLC1, except it furthercontains 0.15 wt % of the product of EX4.

Lubricant Example 9

(LC9) is similar to CLC4, except it contains 0.26 wt % of the product ofEX2.

Lubricant Example 10

(LC10) is similar to CLC4, except it contains 0.35 wt % of the productof EX3.

Lubricant Example 11

(LC11) is similar to CLC4, except it contains 0.35 wt % of the productof EX4.

Testing

Lubricant examples LC1 to LC8 and comparative Lubricant examples CLC1 toCLC3 are evaluated in the following ASTM tests D445, D4684-07 andD5985-02. The lubricants are also evaluated in Chrysler's FFV emulsionstability test.

ASTM D445 relates to measurement of kinematic viscosity (units mm²/s) at100° C.

ASTM D4684-07 (Mini-Rotary Viscometer or MRV) relates to thelow-temperature pumpability of an engine lubricating oil. Yield stressand low-shear-rate viscosity are measured after cooling at controlledrates over a period exceeding 45 hour to a final test temperaturebetween −10° C. and −40° C. The units are Centipoise (cP) or mPa·s.

D5985-02 covers the determination of pour point of petroleum products byan automatic instrument that continuously rotates the test specimenagainst a suspended detection device during cooling of the testspecimen.

The Chrysler FFV emulsion stability test involves the steps of combining10 volume % E85 fuel, 10% water, and 80% fully formulated engine oil andmixing them in a Waring blender. The resultant emulsion is stored ingraduated cylinders at 0° C. and room temperature (25° C.) for 24 hours.At the end of the test, the volume percent oil (% oil), percent emulsion(% emul), and percent water (% H₂O) are recorded. Typically, aformulated oil is considered to pass the FFV test if % H₂O at both 0° C.and room temperature is zero.

The results obtained for the tests described above are as follows:

Test D445 D4684-07 (at −35° C.) CLC1 10.33 32400 CLC2 10.62 30900 CLC310.60 32300 LC1 n/m n/m LC2 n/m n/m LC3 10.54 30500 LC4 10.54 31300 LC510.45 44500 LC6 10.43 66000 LC7 10.65 36300 LC8 10.66 46500

Chrysler FFV at 0° C. Chrysler FFV at 25° C. % oil % emul % H₂O % oil %emul % H₂O CLC1 86 0 14 85 0 15 CLC2 87 0 13 84 0 16 CLC3 88 0 12 84 015 LC1 n/m n/m n/m 12 88 0 LC2 n/m n/m n/m 3 97 0 LC3 18 82 0 52 48 0LC4 6 94 0 15 85 0 LC5 7 94 0 3 97 0 LC6 23 77 0 1 99 0 LC7 9 91 0 40 600 LC8 5 95 0 26 74 0Footnote to the tables:

-   -   n/m indicates a data point not measured

Examples CLC4 and LC9 to LC11 are analysed for pour point performance bythe methodology of ASTM method D5985-02. The results obtained are asfollows:

Example Pour Point (° C.) No Flow Point (° C.) CLC4 −18 −19.9 LC9 −18−21 LC10 −30 −30.1 LC11 −30 −30.1

Overall the results obtained for the block copolymer of the presentinvention indicate that the polymer has emulsifying properties and/orpour point depressant properties.

It is known that some of the materials described above may interact inthe final formulation, so that the components of the final formulationmay be different from those that are initially added. The productsformed thereby, including the products formed upon employing lubricatingcomposition of the present invention in its intended use, may not besusceptible of easy description. Nevertheless, all such modificationsand reaction products are included within the scope of the presentinvention; the present invention encompasses lubricating compositionprepared by admixing the components described above.

Each of the documents referred to above is incorporated herein byreference. Except in the Examples, or where otherwise explicitlyindicated, all numerical quantities in this description specifyingamounts of materials, reac- tion conditions, molecular weights, numberof carbon atoms, and the like, are to be understood as modified by theword “about.” Unless otherwise indicated, each chemical or compositionreferred to herein should be interpreted as being a commercial gradematerial which may contain the isomers, by-products, derivatives, andother such materials which are normally understood to be present in thecommercial grade. However, the amount of each chemical component ispresented exclusive of any solvent or diluent oil, which may becustomarily present in the commercial material, unless otherwiseindicated. It is to be understood that the upper and lower amount,range, and ratio limits set forth herein may be independently combined.Similarly, the ranges and amounts for each element of the invention maybe used together with ranges or amounts for any of the other elements.Multiple groups represented by the same symbol in the formulae describedabove, may be the same or different.

As used herein the “C₁₋₃₀ alkyl (meth)acrylic units” relate to productformed by the polymerisation of C₁₋₃₀ alkyl (meth)acrylic monomer. TheC₁₋₃₀ alkyl (meth)acrylic units may then be used to form the block(s) asdescribed herein above. Reference to the percentage of C₁₋₃₀ alkyl(meth)acrylic units is considered as a mole percent.

As used herein, the term “hydrocarbyl substituent” or “hydrocarbylgroup” is used in its ordinary sense, which is well-known to thoseskilled in the art. Specifically, it refers to a group having a carbonatom directly attached to the remainder of the molecule and havingpredominantly hydrocarbon character. Examples of hydrocarbyl groupsinclude:

-   -   (i) hydrocarbon substituents, that is, aliphatic (e.g., alkyl or        alkenyl), alicyclic (e.g., cycloalkyl, cycloalkenyl)        substituents, and aromatic-, aliphatic-, and        alicyclic-substituted aromatic substituents, as well as cyclic        substituents wherein the ring is completed through another        portion of the molecule (e.g., two sub stituents together form a        ring);    -   (ii) substituted hydrocarbon substituents, that is, substituents        containing non-hydrocarbon groups which, in the context of this        invention, do not alter the predominantly hydrocarbon nature of        the substituent (e.g., halo (especially chloro and fluoro),        hydroxy, alkoxy, mercapto, alkylmercapto, nitro, nitroso, and        sulphoxy);    -   (iii) hetero substituents, that is, substituents which, while        having a predominantly hydrocarbon character, in the context of        this invention, contain other than carbon in a ring or chain        otherwise composed of carbon atoms, and encompass substituents        as pyridyl, furyl, thienyl and imidazolyl; and    -   (iv) heteroatoms, including sulphur, oxygen, and nitrogen. In        general, no more than two, preferably no more than one,        non-hydrocarbon substituent will be present for every ten carbon        atoms in the hydrocarbyl group; typically, there will be no        non-hydrocarbon substituents in the hydrocarbyl group.

While the invention has been explained in relation to its preferredembodiments, it is to be understood that various modifications thereofwill become apparent to those skilled in the art upon reading thespecification. Therefore, it is to be understood that the inventiondisclosed herein is intended to cover such modifications as fall withinthe scope of the appended claims.

1-28. (canceled)
 29. A method of operating an internal combustion engine of a vehicle fueled with a mixed gasoline/alcohol fuel, comprising supplying to the engine a lubricating composition comprising an oil of lubricating viscosity and a block copolymer having emulsifier properties, wherein the block copolymer comprises a diblock comprising: (a) a hydrophobic first block having C₁₋₃₀ alkyl (meth)acrylic units, wherein the C₁₋₃₀ alkyl (meth)acrylic units comprise C₁₂₋₁₈ alkyl methacrylic units, with the proviso that alkyl groups of the C₁₋₃₀ alkyl methacrylic units have an average total number of carbon atoms of at least 8; and (b) a second block having C₁₂₋₁₈ alkyl methacrylic units which further have a non-carbonyl heteroatom-containing group providing a polar group to such units, the heteroatom-containing group derived from a nitrogen-containing group, whereby said second block exhibits greater hydrophilicity than does the hydrophobic first block, wherein the mixed gasoline/alcohol fuel contains from 5 wt % to 85 wt % alcohol.
 30. The method of claim 29, wherein the block copolymer is present in an amount from about 0.01 wt % to about 0.5 wt % of the lubricating composition.
 31. The method of claim 29, wherein the block copolymer is present in an amount from about 0.05 wt % to about 0.3 wt % of the lubricating composition.
 32. The method of claim 29, wherein the block copolymer is present in an amount from about 0.01 wt % to about 0.05 wt % of the lubricating composition.
 33. The method of claim 29, wherein the internal combustion engine is a flexible fuel vehicle engine.
 34. The method of claim 29, wherein at least 50 wt % of the C₁₂₋₁₈ alkyl methacrylic units are C₁₂₋₁₅ alkyl methacrylic units.
 35. The method of claim 29, wherein at least 70 wt % of the C₁₂₋₁₈ alkyl methacrylic units are C₁₂₋₁₅ alkyl methacrylic unit.
 36. The method of claim 29, wherein at least 80 wt % of the C₁₂₋₁₈ alkyl methacrylic units are C₁₂₋₁₅ alkyl methacrylic units.
 39. The method of claim 29, wherein the nitrogen containing group contains a monomer selected from the group consisting of dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, dimethylaminopropyl methacrylate, dimethylaminopropyl acrylate, dimethylaminopropylacrylamide, dimethylaminopropyl-methacrylamide, and mixtures thereof.
 40. The method of claim 6, wherein the nitrogen-containing monomer is dimethylaminoethyl methacrylate.
 41. The method of claim 29, wherein the block copolymer is a methacrylate polymer.
 42. The method of claim 29, wherein the block copolymer is a linear diblock copolymer.
 43. The method of claim 29, wherein the block copolymer is obtained from a controlled radical polymerisation process or other living polymerisation process.
 44. The method of claim 43, wherein the controlled radical or other living polymerisation process is one of RAFT (Reversible Addition Fragmentation Transfer), ATRP (Atom Transfer Radical Polymerisation), nitroxide-mediated or anionic polymerisation.
 45. The method of claim 44, wherein the controlled radical polymerisation process is a RAFT process.
 46. The method of claim 29 wherein the block copolymer has a weight ratio of first block to second block from 1:6 to 1:18.
 47. The method of claim 29, wherein the alcohol of the mixed gasoline/alcohol fuel is ethanol.
 48. The method of claim 29, wherein the mixed gasoline/alcohol fuel contains from 10 wt % to 85 wt % alcohol.
 49. The method of claim 29, wherein the mixed gasoline/alcohol fuel contains from 15 wt % to 85 wt % alcohol. 